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Finally had some free time so got the front torn down again so I can install my refurb'd rotor...
I'm thinking I shoulda painted this or the caliper a different color from each other. They might clash, but I'll know soon enough..


The rotor before getting pampered and the spacer that needed machining. Decided to weld a dust cover for the seal since the 400s axle spacer had one.
[atachment=83757]image-23.jpg[/attachment]

I finally got the front squared away brake wise, just waiting for my banjos so I can make some brake lines.
So moved towards the back and fabbed up a new brake stay. I think it came out pretty decent, still gonna brace it a little on the earlier fabbed spacer for the wheel.
Adjustable mount I milled out for the new brake stay. Made it too adjustable though.



New location for said mount..


A top view of it all together..


side shot..


Bottom looking towards the back..


Originally I was gonna take a .120 wall tube and cut it in half to make a C shape, then have that rest on top of the swingarm. I'm sure it wouldn't have moved once the axle nut was tighten down. So I think I went a lil overboard? Now just gotta figure out how to get the lever connected once I get my new rearsets on/fabbed.

All that's left is a brake line(on it's way, Thanks Mike), fiddle with tire a bit to get it to seat squarely around the rim. Mechanically, the front is 90% done more or less. Mounting 90/90 Avons with a tube is a little tough.


Should I air the tube up to what the tire would hold tubeless?

ed

rear tire mounted.


Gonna paint the brake housing and cush hub. Or maybe polish it a bit so it'll match the hub? Then back in it's place.

Great looking fabrication, and I like what you're doing with the bike, but that rear brake is worrisome.

Whereas the rear brake stay originally had a good lever advantage over the rear wheel torque by virtue of the fact that the stay was holding the hub from several inches away from the center, the new setup gives the wheel a huge lever advantage over the spacer-attached stay. Secondly, the original stay was a bar under tension which is very strong, whereas the new stay is a bar under torsional stress, which is far more prone to a tearing action where the majority of the load is at one point, initially (much like the difference in tearing a piece of paper versus pulling the paper apart all at once).

I've seen a few ill-engineered stays result in the hub rotating and wrapping the brake rod around the hub during a hard stop.

I would have to agree.
Steve

loudhvx wrote: Great looking fabrication, and I like what you're doing with the bike, but that rear brake is worrisome.

Whereas the rear brake stay originally had a good lever advantage over the rear wheel torque by virtue of the fact that the stay was holding the hub from several inches away from the center, the new setup gives the wheel a huge lever advantage over the spacer-attached stay. Secondly, the original stay was a bar under tension which is very strong, whereas the new stay is a bar under torsional stress, which is far more prone to a tearing action where the majority of the load is at one point, initially (much like the difference in tearing a piece of paper versus pulling the paper apart all at once).

I've seen a few ill-engineered stays result in the hub rotating and wrapping the brake rod around the hub during a hard stop.

Thanks loud for the compliment I totally understand what you're saying and sure as hell don't wanna be another statistic to that category. I've seen and repaired a fair share of head scratching fabrication whoas (like, whoa is that gonna be safe or work how intended?)that has come through my shop and I always take mental note. If you ever have the chance to look over the entire chassis of a sandrail or long travel in person, you'll see a few areas questionable. The material I used was 1" x 1/4" chromoly plate and round stock. Now the way I fit the pieces together before welding further strengthens the joint. In the round stock, I machined a channel for each arm to sit in, then I chamfered the edge of where the weld would be so I'll get maximum penetration. I made a 10x1.50 steel bung and welded it to the arm that gets bolted to the swing arm to fill in the gap. I'm pretty confident that it should hold up just fine. Once finally I get this bike on the road I'll definitely keep my eyes on it. I should've taken a picture of how I did, but I was antsy and wanted to finish that part and move on.
I do appreciate your concern though loud none the less. I know problems will surely present themselves once the bike gets on the road, I'm hoping and trying to keep it from being fabrication problems caused by me. Chances are, the way I have the rear brake set up now, it may change? I didn't cut the tabs for the original setup just in case.


ed

I'm going to chime in here.
2 reasons you should reconcider.
1) Unsprung weight, how much do the fabricated mounts and axle spacer
along with filler rod used weigh compared to the stock spacer and rod?
This issue is minor and the lesser of the two.
2) The more serious problem will be when the axle bolt is tightened down.
The friction will prohibit the rotation of that axle spacer. This will affect both
directions of travel. Both in the application and the release of the brake.


.

Well I hope you don't get hurt, but here are some numbers to consider:

Lets assume the OD of the tire is 22 inches, the stock brake stay location is 4 inches from the center of the axle, and the fabricated stay is 1/2 inch from the center of the axle.

The wheel/tire has a 11:4 lever advantage over the stock brake stay. That is 2.75.
The wheel/tire has a 11:1/2 lever advantage over the fabricated stay. That is 22.0

That is an 8 fold increase in the torque the fabricated brake stay has to handle. But that is only part of the story.

Look at how much aluminum is used on the hub to reinforce the bolt that holds the brake stay. That ensures the stock brake stay merely has to handle the torque in a purely tensile load.

The fabricated arm is designed such that the arm has to handle the torsional load with no reinforcement. This means the backside of the arm is holding all of the tension while the front is acting like a fulcrum. This is another lever trying to tear the arm from the base metal.

The way it is set up is analogous to having a wheel with one single large spoke to handle the torque.

Can you at least box section the two arms together so they help each other?
Imagine if you made the spacer about 8 inches in diameter, then simply bolted the spacer to the hub and swingarm at the same points you have them now, then milled away all of the excess metal. You would end up with a pie-shaped wedge attached to the spacer. Then you would hollow it out. This way the torque is transferred from hub to frame somewhat directly.

You could put the attachment point on the underside of the swingarm so the box section could be more like a rectangle than a wedge.

As a side note, will the brake lever still work even though it will be pulled the opposite direction? Some levers can go either way. Or were you going to make the brake rod a push-type instead of pull?

Something that just occurred to me is, when the bike is being ridden, power is applied to the wheel, stress is present at the end of the swing arm at the axle. A certain amount of flex can occur. If braking is applied, the end of the arm is under more stress. With the break arm fastened close the pivot and frame, the braking force is transferred there, not to the end of the arm.
If that makes any sense.
Steve

Subscribed! This build has definitely grabbed my curiosity!

Didn't forget about you forum! Life took me away from you guys. JK..well not too much really. As to not bore anyone with my life the past month or so, I m gonna stay on topic and fill you in on that. Sadly I haven't been able to get hardly anything done on my bike which pisses me off! thanks personal life..another story. Just been picking at things here and there when I had the time. I don't have all the pics on hand, but I'll get them up ASAP..Make a small list of things so far..

Front brake is finally 100% Has fluid and bled. Goodridge lines (purchased from 79MKII, thank you) replaced the stocks. (I did however change 2 hose ends out for a 45 and 90 banjo for a better fit (sorry Mike ) No pic on hand, but I'll get it.
Months ago, I did an impulse buy on some forktube headlight mounts.
eBay forktube headlight mounts..


Didn't like how much it made the light stick out so made me some new ones.


sucked in a lot more..


That's really all the progress I've made the past month. Aside from finishing/shortening the harness since I removed the self canceling signal unit and the new electrical box/tray under the (soon to be where my ass is suppose to) seat. Secured the throttle and clutch cable to the frame. New chain put on, Got the clip-ons under the top triple (which reminds me of something). Still a bunch of work left. I still need to get some rearsets on. The stock ignition switch is buggin me how it sticks up so high now? A concern a few post ago of how I have the rear brake setup is still not set in stone. That will be addressed later on before the bike gets underway. Need to finish a seat and a clever(or not so clever)way to mount it. The tail section, I have to get that mediocre cowl looking thing I got going on, into aluminum or other easy working material after I finalize a shape of it. So far it's just a cover for the battery. So yeah...bunch of work left. I'm looking forward to it also! Now I just have to turn off the nice guy be that asshole when some needs MY help?

Don't know if you can see what's going on here? lol

A guzzi in the back of fords new transit?

remade the tire chock to bolt down..


couldn't say no to this guy since he was the one that gave me the bike in the first place.